The invention relates to a method for the reproduction of pictures having different resolutions.
On a video CD, the video data for moving pictures are stored in a standard resolution, which, e.g. for the PAL system, is 352*288 pixels at a frame frequency of 25 Hz. The video data for still pictures can be stored either with this resolution or with an increased resolution of 704*576 for the PAL system. Consequently, depending on the specification, for still pictures on a video CD, there may also be a data stream having a mixed resolution in addition to a data stream having a standard resolution.
More detailed specifications regarding the stored data are stored in a separate list, which have to be read out during reproduction by a player. This process requires special manipulation by the player by means of suitable software.
The invention relates to a method for the reproduction of pictures having different resolutions.
The invention is achieved by means of the features specified in claim 1.
Advantageous developments are reproduced in the sub-claims.
According to the invention, during the reproduction of pictures, in particular still pictures, a preliminary analysis is carried out which searches through the data stream present on a storage medium, e.g. a video CD or a magnetic recording medium, for different resolutions. Only so-called I frames are analysed in this case. These are coded pictures whose contents are based exclusively on the information in a picture. If an I frame having an increased resolution has been found, it is read immediately from the storage medium for further processing.
However, if only I frames having a standard resolution are found, two different decoding steps are afforded. On the one hand, a jump can be initiated back to the beginning of the I frame having a standard resolution or the data having a standard resolution are read out during the preliminary analysis and buffer-stored in a buffer.
Separate checking as to whether a still picture to be reproduced is stored with an increased resolution on the video CD is advantageously avoided by the inventive method. The method is preferably employed for displaying menu contents.